US 12,436,201 B2
Method and system for evaluating strength of voltage source converter (VSC)-penetrated power grid based on voltage stiffness
Ying Huang, Hangzhou (CN); Guoteng Wang, Hangzhou (CN); and Zheng Xu, Hangzhou (CN)
Assigned to ZHEJIANG UNIVERSITY, Hangzhou (CN)
Filed by ZHEJIANG UNIVERSITY, Hangzhou (CN)
Filed on Oct. 22, 2024, as Appl. No. 18/922,765.
Application 18/922,765 is a continuation of application No. PCT/CN2024/109279, filed on Aug. 1, 2024.
Prior Publication US 2025/0044371 A1, Feb. 6, 2025
Int. Cl. G01R 31/40 (2020.01)
CPC G01R 31/40 (2013.01) 14 Claims
OG exemplary drawing
 
1. A method for evaluating strength of a voltage source converter (VSC)-penetrated power grid based on voltage stiffness, comprising:
step (1) acquiring a first data corresponding to a to-be-analyzed power gird in real time, and processing the first data to generate a first admittance matrix corresponding to the to-be-analyzed power grid; wherein the first data is basic planning data of the to-be-analyzed power grid, the first admittance matrix is an original node admittance matrix, the to-be-analyzed power grid comprises a plurality of VSCs respectively corresponding to a plurality of VSC nodes, and the plurality of VSCs comprises a grid-forming VSC and a rated alternating-current (AC) bus voltage grid-following VSC;
step (2) processing the first admittance matrix to generate device impedance data of each of the plurality of VSCs in the to-be-analyzed power grid and a second admittance matrix corresponding to the to-be-analyzed power grid; wherein the second admittance matrix is a corrected node admittance matrix;
step (3) removing rows and columns where a grid-forming VSC node and a rated AC bus voltage grid-following VSC node are located from the second admittance matrix to generate a third admittance matrix;
step (4) processing the third admittance matrix to generate a second data and a third data corresponding to each of the plurality of VSC nodes; wherein the second data is a Thevenin equivalent impedance data of an external system of each of the plurality of VSC nodes, and the third data is voltage stiffness data of each of the plurality of VSC nodes; and
step (5) generating strength evaluation data corresponding to the to-be-analyzed power grid based on the third data in combination with the second data;
wherein the step (5) further comprises:
determining, in real time, whether the external system corresponding to the to-be-analyzed power grid is a strong system based on the strength evaluation data; wherein if the voltage stiffness data is greater than 0.95, the external system is regarded as the strong system.